In the art of tightening bolts or screws of a joint it is often desirable to tighten the joint as rapidly as possible. A conflict arises in the fact that the there is also a desire not to overshoot a set target torque. For a hard joint this may typically imply that a rapidly rotating motor needs to be retarded from a high angle velocity to a stop in a fraction of a lap as the torque starts to increase in a joint.
In order to decrease the tensions in a power tool it is known to arrange a spring to receive the reaction forces above a certain magnitude. Typically the motor is connected via at least one reduction gear to the output shaft. The gear may include a load sensitive part, i.e. a part that affected by the reaction torque from the output shaft. In a planetary gear the gear rim may typically constitute a load sensitive part that may be allowed to rotate when the torque of the motor is not completely installed into the joint.
The arrangement of such a spring is typically relatively space demanding and complex. Normally such an arrangement includes bearings and attachment pieces for securing the ends of the spring to the housing and the load sensitive part of the gear, respectively.
Hence, there is a need of an arrangement that offers flexibility with respect to the distribution of forces during a tightening operation, but which is easy to produce and mount to a complete and functional power tool.